Telephone system



um v 3 3 8 R. L. STOKELY TELEPHONE SYSTEM Filed Sept. 23, 1930 En NFQQSum W338 65 W ammo March 29, 1932.

Patented Mar. 29, 1932 RAY L. STOKELY, OF FLORAL PARK, NEW YORK,ASSIGNOR TOIBELL TELEPHONE LABORATORIES,- INCORPORATED, NEW YORK, N. Y.,A CORPORATION OF NEW YORK TELEPHONE SYSTEM Application filed September28, 1930'. Serial No. 483,821. I

the call, and to simplify the circuit arrange ments for the controlofsuch meters in standard telephone systems. i I

Heretoforesystems have been proposed, in which a meter and circuitarrangement are so arranged that the meter may be added directly inparallel with the cut-off relay to any standard line circuit andcontrollable 15 over the sleeve circuit to remain in an unoperativecondition, while ground is applied to the sleeve circuit for theoperation of the cut-elf relay, and to operate each time the boosterbattery is substituted for the ground connection. I r

A feature of this invention is an improved meter and circuit arrangementwhich may" be added to'and controlled over a single con,-

ductor in the above manner According to this feature, themeter isprovided with two windings differentially wound and marginal incharacter, and the circuit, arrangement is such that when" ground issubstituted current in one winding becomes effective to cause the meterto release quickly. 7 In this manner the releaseof the'meter is assuredafter each charging operation without interfering with the operatedcondition of the cut-0d relay. a

This invention has been shown in the accompanying drawing applied to anautomatic connection between a calling subscriber and a calledsubscriber through switches indicated in diagrammatic form.

Referring to this drawing the service meter 3 has been. shown associatedwith the cir-' cuftslof a calling subscribers line whose set isindicated at l. The connection may be established from this subscribe'rsline 45 through line finder LE, selector Sand consubscriber at 2 willnow be described in con-' nector C to thecalled subscribers line, whoseset is indicated at 2. These switches and associated circuits may be ofthe usual type employedin automatic telephone systems in which a groundconnection is established .over the sleeve conductors, when theconnection is extended therethrough. Control circuits for the servicemeter 3have been shown associatedwith the line ,finder LF containingcertain interrupting devices used in the control. The interruptingdevice 5 may be arrangedto close through spring contacts connection toground once every six seconds. For example, the ground connections maybe closed for, one-quarter second andopened for five and three-quarterseconds The interruptfing' device 6 may be arranged to close connectionsto ground, for example,for onerquarterse'cond and leave theseconnections open for two seconds. The two interrupting e devices 5 and6may be driven by any well known, time regulated, constantly drivenpower means. may be arranged to operate spring contacts under control ofthe stepping magnet 8-so The interrupting device 7 r.

thatthe connections are shifted once every sixtieth opertion of thestepping magnettS; The establishing of a connection between the calling;subscriber at 1 and the called and ring conductors through thesubscribers loop at 1. Relay 10 in operatingcloses a connection toground at its armature and'front I contact to cause in the usual mannera line finder such asLF to connect with the call-f ing subscribers lineand establish the usual ground connection on the slc ve conductor.

This ground connection now causes the operation of cut-off relay 11 byclosing the circuit from battery, winding of this relay to round throughthe sleeve terminal and brush of the line finder LF. The circut forrelay 10 is thereby opened at the left hand armatures and back contactsof relay 11 so that relay 1O releases and the connection is now undercontrol of the ground on the sleeve of the line finder while relay 11 isheld operated by this ground. The service meter 3 which is of a marginalcharacter will not operate in this circuit closed from ground on thesleeve through its windings to battery 20.

The subscriber at 1 now dials the number of the desired subscriber andthe connection is thereby extended through the selector S and connectorC to the called subscribers line at 2 in the usual manner. Vhile thisC()111'1C tion is being extended the ground connection on the sleeveconductor is also extended through to the connector in the usual manner.When the called subscriber answers the usual automatic ringing, bylifting the receiver off the switchhook, the talking connection isestablished through the tip and ring conductors between the twosubscribers lines.

This talking connection now causes the operation of relay 12 which has awinding in each conductor. Operation of relay 12 initiates the functionsof the control circuits for service meter 3, by closing a circuit forthe operation of relay 13 as follows: battery, right hand winding ofrelay 13, armature and front contact of relay 12, inner left handarmature 16 and back contact of relay 13, right hand armature and backcontact of relay 14, upper closed contacts of the springs controlled byinterrupter 7 and to ground through the lower springs controlled byinterrupter 6, when this latter interrupter closes this connection. Sucha closure may occur any time within two seconds after the operation ofrelay 12. This circuit for relay 13 only causes it to partially operateto close a connection for its left hand winding through its right handarmature 15 and front contact to the ground on the sleeve conductor. Aslong as the original circuit for the relay 13 remains the left handwinding will be short-circuited, but when it is opened at the end ofone-quarter second period, the short circuit is removed. The circuit forrelay 13 will then extend from battery through its right hand winding,armature and front contact of relay 12, left hand winding of relay 13and its right hand armature 15 and front contact to ground on thesleeve. Both windings are energized and the remaining armatures 16 and17 of the relay are thereby attracted.

The contacts of interrupter 6 will now remain open for two seconds. Atthe end of this period the connections to ground are again establishedand a circuit completed for the operation of relay 18 from battery,winding of this relay, inner left hand armature 16 and front contact ofrelay 13, right hand armature and back contact of relay 14, upper normalcontacts controlled by interrupter 7 and contacts controlled byinterrupter 6 to ground. Relay 18 in operating opens the connection toground for the sleeve conductor, from the line finder and the callingsubscribers line, at its right hand make-beforebreak contacts andestablishes a connection to a so-called booster battery 19 through theright hand armature and front contactover the sleeve through the linefinder. The service meter 3 is thereby operated as follows: The windingsof the service meter are in a series opposing connection with battery20. \Vhen the booster battery 19, is connected through the inner righthand armature and front contact of relay 18, over the sleeve conductorof the line finder and the windings of the service meter 3 to battery 20to ground the service meter 3 will operate as the battery 20 is of theopposite polarity to that of booster battery 19. The inductance of theright hand winding of service meter 3 is lower than that of the lefthand winding so although the current in these windings produce opposingflux the meter will operate due to stronger flux in the left handwinding. The service meter in operating registers the first period ofconversation. While booster battery 19 is applied by relay 18 thecut-off relay 11 will remain operated over the same circuit from thebooster battery through the winding on relay 11 to the battery at theother end of this winding to ground, as this latter battery is of thesame polarity as battery 20. Relay 11 will, therefore, operateregardless of whether ground or booster battery is connected to thesleeve.

Relay 18 also closes a. circuit for the operation of stepping magnet 8from battery, winding of this magnet, the outer left hand armature andfront contact of relay 18 to ground. The stepping magnet is therebyactuated and when it releases as hereinafter will become apparent itactuates the interrupter 7 for control of the associated springcontacts, to open the normal connection to ground through the lowercontacts, to open the connection through the upper contacts and to closea connection to ground for its middle contact.

When relay 18 is released due to the opening of the connection to groundat the interrupter 6 after the one-quarter second period the servicemeter is deenergized and the ground. on the sleeve is restored tomaintain cut-ofi' relay 11 operated. It should be noted that on theoperation of the service meter 3 a circuit is completed at its armatureand front contact to ground I This completes a circuit from battery 20throughthe right hand winding of the service. meter" 3 to ground. This.circuit causes a current to 5 flow in the right hand winding in adirec.-.

ing lower than the inductance of the left hand winding. In fact theconditions may be such that very little if any change takes place intherelative flux characteristics in the meter from that produced by thebatteries 19 and alone. On the other hand when the boosterbattery 19is'removed by the release of relay18- andground substituted in thesleeve circuit, the current in the left hand winding of the meter willbe discontinued and-the current through the right hand winding which isin the opposite direction,

- will remain for a short period to hasten the release of the meter; Inother words, the

flux produced by the right 1 hand Winding causes the flux produced :bythe left hand winding to. be neutralized'more rapidly than wouldordinarily be the casein a relay having a single winding and theservicemeter will therefore be released quickly.

A circuit will now be completed, due to the operation of the"contactscontrolled by interrupter 7 when'the magnet 8'releases relay 14from battery, winding of this, relay, outerleft hand armature 17; andfrontcontact of relay 13 to ground atthe' middle contact of interrupter7. Relay 14 in operating causes, due to the release of relay 16, asecond circuit to be completed for the stepping magnet 8 from battery,windingfiof the magnet, outer left hand armature and back contact ofrelay 1 8, inner right hand armature and front contact ofrelay. 14 togground through the springs controlled Iby interrupter 5; As stated thisinterrupter causes a connection to be established to ground once everysix seconds. The stepping magnet 8 will now, therefore,-be operatedonceevery six secondsfor one-quarter second each time to controlthe'interrupter 7, until sixty steps have been taken by the steppingmagnet 8 when the interrupter 7 has been rotated to 1 again restore thecontacts to the normal condition. When this takes place the relay 14will bereleased due to the opening of the circuits for this relay attirecontacts controlled by interrupter 6, unless thecontacts of interrupter7 arerestored at the time the time elapsed at this moment will besix'minon the release'of relay 18,ffor the operation of the circuit ascontacts' controlled by interrupter 6 are closed in which case relay14will bemaintained operated until these latter contacts are again opened,which will always be within the one-quarter second period. The circuitfor maintaining relay 14; operated will in thiscase be extended frombattery, Winding and right hand armature and front contact ofrelay"14,upper contacts controlled by-interrupter 7 to ground at thecontacts controlled l by interrupter 6. The maintenance of relay 14,operated under these circumstances is to prevent the subsequentoperation of relay 18 Y I to take .place for less than one-quartersec-0nd. If on the-other hand the closing of the connection by interrupter 7occurs when the connections through the contacts controlled byinterrupter 6 are open, relay 14 will be released immediately. In eithercase the subsequent operation of relay '18 ,will occur within the periodof two seconds and be maintained operated for a period of one-c quartersecond.

It should be observed therefore that the utes since the operation of theservice meter plus a few seconds which may vary depending on the timethe called subscriber lifts r his receiver off the hook as compared withthepositions of theinterrupters 5 and 6 at thattimer If the conversationis to be maintained beyond this first conversational period, theoperationsjust described will be repeated; In otherfwords,when relay 14g is released and a connection to ground is 400 again established at theinterrupter 6,relay 16 will be operated as heretofore described forone-quarter of a secondto again cause" the operation of service meter 3to registera second conversational period. If-

the subscribers now release the connection during the second period,relay 12 will be released and thus cause the release of relay 13. .Relay13 in releasingrwill close the cir cuit forithe operation of thestepping magnet back contact of relay 13 and'the middle closed 1contacts of interrupter 7 to ground. When interrupter 7 is returned tonormal, this connection to ground will be opened and the stepping magnetwill not be operated further. connect-ion until the second period ofconversation is ended and then releases it, relays 12 and 13'willrelease and when relay14'is released, no further actions take place inerated. r

VJhile this invention has been illustrated in 7 connection with but asingle telephone system, it should be understood that it may,

readily be applied toa number of other. cir- 1301 In case a subscribermaintains the 120.

relay 18 cannot then be opcuit arrangements without departin from thespirit thereof which should be imited only by the scope of the appendedclaims.

What is claimed is 1. In combination, two sources of current, a. magnethaving two windings, a circuit for said magnet windings, means forclosing said circuit from one source to ground, said magnet remaininginoperative in said circuit, a second circuit for said magnet windingsincluding both said sources, means for substituting said second circuitfor said first circuit, said magnet being operative in said secondcircuit, and a third circuit closed by the operation of said magnet forshuntin one winding and energizing the other winding of said magnet tohasten the release of said magnet when said first circuit is againclosed.

2. In comibnation, two sources of current, a magnet having two windings,a relay, a circuit for said magnet windings and said relay, means forclosing said circuit from one source to ground, said magnet remaininginoperative in said circuit and said relay operative in said circuit, asecond circuit for said magnet windings and said relay including bothsaid sources, means for substituting said second circuit for said firstcircuit, said magnet being operative in said second circuit and saidrelay remaining operative in said second circuit and a third circuitclosed by the operation of said magnet for shunting one winding and forenergizing the other winding of said magnet to hasten the release ofsaid magnet when said first circuit is again closed.

3. In combination, two sources of current, a magnet having two windings,a circuit for said magnet windings, means for closing said circuit fromone source to ground, said magnct rcn Wining inoperative in sa dcircuit, a second circuit for said magnet windings including both saidsources, means for substituting said second circuit for said firstcircuit, said magnet being operative in said second circuit, and a thirdcircuit closed by the operation of said magnet and including one of itswindings and the first source for energizing said one winding and forshunting the other winding when said first circuit is again closed tohasten the release of said magnet.

4. In combination, two sources of current of diflt'erent potential, amagnet having two windings, a circuit for said magnet windings, meansfor closing said circuit from the lower potential source to ground, saidmagnet remaining inoperative in said circuit, a second circuit for saidmagnet windings including both said sources, means for substituting saidsecond circuit for said first circuit, said magnet being operative insaid second circuit, and a third circuit closed by the operation of saidmagnet for shunting one of its windings from the low potential sourceand for energizing the other winding from said low potential source whensaid first circuit is again closed to hasten the release of said magnet.

5. In combination, two sources of current of different potential, amagnet having two windings, a relay, a circuit for said magnet windingsand relay means for closing said circuit from the lower potential sourceto ground, said magnet remaining inoperative in said circuit and saidrelay operative in said circuit, a second circuit for said magnetwindings and said relay including both said sources, means forsubstituting said second circuit for said first circuit, said magnetbeing operative in said second circuit and said relay remainingoperative in said second circuit, and a third circuit closed by theoperation of said magnet for shunting one of said windings from thelower potential source and for energizing the other winding from saidlower potential source when said first circuit is again closed to hastenthe release of said magnet.

6. In combination, two sources of current, a magnet having two windings,a circuit for said magnet including both windings in series with onesource, means for closing said circuit to ground, said magnet remaininginoperative in said circuit, a second circuit for said magnet includingboth windings in series with both sources. means for substituting saidsecond circuit for said first circuit, said magnet being operative insaid second circuit. a third circuit closed by the operation of saidmagnet for including said first source in series with one winding ofsaid magnet to ground and for shunting the other winding to ground fromsaid first source when said first circuit is again closed to hasten therelease to said magnets.

7. In combination two sources of current, a magnet having a firstwinding of lower ampere turn characteristic and a second winding ofhigher ampere turn characteristic, a circuit for said magnet includingboth windings in series with one source, means for closing said circuitto ground, said magnet remaining inoperative in said circuit, a secondcircuit for said magnet including both windings in series with bothsources, means for substituting said second circuit for said firstcircuit, said magnet being operative in said second circuit, a thirdcircuit closed by the operation of said magnet for including said firstsource in series with the lower ampere turn winding to ground and forshunting said higher ampere turn winding to ground from said firstsource when said first circuit is again closed to hasten the release ofsaid magnet.

8. In combination, two sources of current, a magnet having two windingsconnected in series and difi'erentially wound, a circuit for said magnetincluding both windings in series opposing relation and connected to onesource, means for closing said circuit to ground, said magnet remaininginoperative in said circuit, a second circuit for said magnet includingboth windings in series opposing relation and in series with bothsources, means for substituting said second circuit for said firstcircuit, said magnet being operative in said second circuit, a thirdcircuit closed by the operation of said magnet for including said firstsource in series with one winding of said magnet to energize said magnetand for shunting the other Winding of said i magnet When the firstcircuit is again closed to hasten the release of the magnet.

In'witness whereof, I hereunto subscribe my name this 19th day'ofSeptember, 1930,

RAY L. STOKELY.

